The organic electroluminescence (organic EL) display device is a thin display device of self-emission type, and has an advantage of display performance, for example, high visibility or a small viewing angle dependency, in comparison with a liquid crystal display device. Also, in addition to an advantage in that the display can be made lighter and thinner, it has a possibility of achieving a display device having a shape, which has not been realized, by using a flexible substrate.
The organic EL display device has the excellent features as described above. However, since layers having different refractive indexes are stacked using a transparent conductive material having a high refractive index, for example, ITO as an electrode and a metal material having a high reflectance are used, external light is reflected at the interface thereof, thereby causing a problem of reduction of contrast or background reflections due to internal reflection.
In order to inhibit the harmful influence due to the external light reflection, proposals of using an absorption type linear polarizing plate and a circular polarizing plate composed of a λ/4 plate have been made (for example, Patent Documents 1, 2, 3 and 4).